1. Field of the Invention
The present invention relates to a method and an apparatus for recognizing an earphone in a portable terminal. More particularly, the present invention relates to a method of recognizing an earphone in a portable terminal capable of exactly recognizing whether a connected earphone is a 3 pole antenna or a 4 pole antenna, and an apparatus thereof.
2. Description of the Related Art
In recent years, with significant development of information and communication technology and semiconductor technology, supply and use of all types of portable terminals have rapidly increased. In particular, recent portable terminals have developed to include traditional fields as well as other terminal fields. For example, a mobile communication terminal provides multi-media functions such as a TV watching function (e.g., mobile broadcasting such as Digital Multimedia Broadcasting (DMB) or Digital Video Broadcasting (DVB)), a music playing function (e.g., MPEG Audio Layer-3 (MP3)), a moving image playback function as well as a general communication function such as speech call or message transmission/reception.
A portable terminal providing such multi-media functions generally provides an ear jack of 3.5 μl size. A 3 pole earphone and a 4 pole earphone may be mounted in the earphone. Accordingly, there is a need for an approach capable of recognizing a type of an earphone mount in the ear jack, and of performing a function according to the recognized type of the earphone by the portable terminal. To do this, when the earphone is mounted in the ear jack, the portable terminal detects generation of an interrupt signal according thereto, detects a voltage of the generated interrupt signal, recognizes a type of the earphone mounted in the ear jack based on the detected voltage, and performs an operation associated with the recognition result. The portable terminal may recognize an operation state of a key (e.g., call key, volume control key, or the like) mounted in the earphone based on the detected voltage of the interrupt signal.
The ear jack includes an interrupt terminal for recognizing a type of an earphone, an operation state of an earphone key, and the like. In a portable terminal of the related art, an interrupt terminal is disposed at an end of an ear jack hole to contact an end of an ear plug inserted in an ear jack hole. However, foreign materials may occasionally be inserted into an ear jack hole while a user is using the earphone, and the foreign materials may make a connection between an ear plug and an interrupt terminal unstable. An issue may arise in which a portable terminal cannot recognize a type of an ear. To address this issue, an interrupt terminal is installed in a side of an ear jack hole.
However, when the interrupt terminal is installed in a side of the ear jack hole, an interrupt signal is generated many times during a procedure of artificially inserting and separating the ear plug. Accordingly, the portable terminal may perform an erroneous operation which the user does not intend. If the user inserts an ear plug for a 4 pole earphone into an earphone hole, an interrupt terminal first contacts a right sound terminal of an earphone and accordingly an interrupt signal is generated and the portable terminal may recognize mounting of a 3 pole earphone. As the ear plug is further inserted into the ear jack hole, connection between a right sound terminal R of an earphone and the interruption terminal is released. According to the generated interrupt signal, the portable terminal may recognize separation of an ear phone.
Subsequently, when the ear plug is completely inserted into the ear jack hole, the interrupt terminal contacts a microphone terminal of the earphone. Accordingly, the interrupt signal is generated and the portable terminal may recognize mounting of a 4 pole phone. Although the portable terminal correctly recognizes that a 4 pole earphone is finally mounted, it may be recognized as ‘separation’ different from intention of a user. Accordingly, the portable terminal may perform an erroneous operation which the user does not intend. For example, as it is recognized as ‘separation’, the portable terminal may erroneously pause a played music.
When the user artificially separates an ear plug from an ear jack, an interrupt signal is generated many times and accordingly the portable terminal may perform an erroneous operation which the user does not intend. In addition, a noise is mixed with an interrupt signal generated while the ear plug is separated from an ear jack. Accordingly, an issue may arise in that an ear jack key (e.g., call key) is pushed in the portable terminal.
Furthermore, a connection state between an interrupt terminal and an ear plug is unstable to generate an interrupt signal and accordingly an erroneous operation may be performed. For example, although the ear plug is not separated from an ear jack, it can be recognized that a connection state of an earphone is separated due to a temporarily unstable connection state. The portable terminal may perform an erroneous operation that pauses a played music according to this recognition. Moreover, the portable terminal may perform an erroneous operation of changing an audio output path from an earphone to a speaker according to the erroneous recognition.